1. Field of the Invention
The present invention relates to a climbing device which is used to climb trees, poles, columns, or the like. In particular, the present invention relates to climbing devices having two main platforms which are alternately raised by the user to obtain a desired elevation on a tree or pole. Furthermore, the present invention relates to climbing devices which have adjustable leveling mechanisms to adjust the angular inclination of the platforms, so that the platforms remain at a horizontal inclination while the user ascends or descends the tree, pole, column, or the like.
2. Discussion of Background Information
A two platform type adjustable tree climbing stand is disclosed in U.S. Pat. No. 5,379,861 to Amacker. A first climbing member has a first upright member gripping structure and movable platform spaced from the upright member to accommodate the body of the user in a sitting position. A second climbing member has a second upright gripping structure and a platform adjacent to the upright member to accommodate the feet of the user. One or both of the climbing members have a retraction device and locking mechanism for adjustably maintaining the climbing members in substantially horizontal position relative to the ground when the climber ascends or descends the tree.
In the case of the above-noted tree stand, the retraction device and locking mechanism include two male sleeves with respective telescoping female sleeves. An outer jaw is connected to the exposed distal ends of the male sleeve. The jaw is positioned on the outside of the tree and then the male sleeves are slid into the female sleeves to connect the platform to the tree. Pins are used to fix the male and female telescoping sleeves together. Resilient biasing members, such as an elastic cord, keep the outer jaw biased against the tree.
The angle of the platforms can be adjusted by pulling on lines attached to pins securing the male and female sleeves together. As a result, the resilient biasing means reduces the length of the telescoping arms and pulls the outer jaw towards the platform with the tree being subjected to a clamping or clasping effect between the outer jaw and the platform.
However, this two platform type tree stand has some disadvantages with its functionality. The resilient member (i.e. an elastic cord) is permanently attached at the bottom of the female sleeve and is manually attached to the most outer end of the male sleeve near the outer jaw. Before the user engages the tree stand to the tree, the user must remove the elastic cord from the telescoping male sleeves, proceed with the installation process of the outer jaw around the tree, reinstall the male sleeves into the female sleeves, and then remember to re-install the elastic cord to the most outer end of the male sleeves near the outer jaw.
In this case, the elastic cord is the only item that holds the platform and the outer jaw together when the security pins are removed for a leveling adjustment. If the user has forgotten to attach the elastic cord, or the elastic cord has broken without knowledge to the user, when extracted, the security pins will allow the outer jaw and telescoping male sleeves to withdraw from the female sleeves affiliated with the platform. As a result, the clasping effect between the outer jaw and the platform is lost, and the platform can become disengaged from the tree unexpectedly. When this occurs, the user of the tree stand can sustain serious injuries from falling out of the stand down to ground level.
Another disadvantage with the two platform type tree stand and the aforementioned retraction cord and locking mechanism is that, even if the user has remembered to attach the cord, the design allows the possibility of the user to inadvertently remove the pins. If that scenario occurs, the weight of the stand and the user's body can easily break the elastic cord. For example, if by error the user decides to extract the security pins to make a leveling adjustment to the first climbing member, and then sits before the security pins have been re-installed, or the user decides to extract the security pins from the second climbing member and stands before the security pins are re-installed, the elastic cord would not have enough strength to support the weight of the user. This would allow the first climber device or second climber device to separate itself from the outer jaw and male sleeves, leaving the climbing member in an unsecured state and the user in a hazardous situation. The same elastic cord failure scenario would apply in the case of a security pin failure. For instance, the security pin can break or may not be re-installed properly into a leveling hole.
There exists a need for a safer and more user friendly tree stand that has adjustable leveling mechanisms that overcome the aforementioned disadvantages.